Optimal stated preference choice experiments when all choice sets contain a specific option

Stated preference choice experiments are routinely used in many areas from marketing to medicine. While results on the optimal choice sets to present for the forced choice setting have been determined in a variety of situations, no results have appeared to date on the optimal choice sets to use when either all choice sets are to contain a common base alternative or when all choice sets contain a "none of these" option. These problems are considered in this paper. © 2004 Elsevier B.V. All rights reserved

Optimal and near-optimal pairs for the estimation of effects in 2-level choice experiments

This paper gives constructions for optimal and near-optimal sets of pairs for the estimation of main effects, and for the estimation of main effects and two factor interactions, in forced choice experiments in which all attributes have two levels. The number of pairs in the sets is much smaller than that in previously constructed optimal 2-level choice experiments. © 2002 Elsevier B.V. All rights reserved

D-optimal orthogonal array minus t run designs

© 2018, © 2018 Grace Scientific Publishing, LLC. This article considers the design performance of orthogonal arrays in which one or more runs are missing at random. We focus on orthogonal arrays of index unity and on the 18 run ternary arrays

Optimal designs for stated choice experiments that incorporate position effects

Davidson and Beaver (1977) extended the Bradley-Terry model to incorporate the possible effect of position within a choice set on the choices made in paired comparisons experiments. We further extend the Davidson-Beaver result to choice sets of any size and show, under a mild restriction, that designs optimal for the multinomial logit model are still optimal. Designs balanced for carry-over effects of all orders can be used to construct designs with a diagonal information matrix for attribute effects. The theoretical results are derived assuming equal merits and we discuss the possible consequences of assuming unequal merits in an example. Copyright © Taylor & Francis Group, LLC

Choosing a Doctor: Does Presentation Format Affect the Way Consumers Use Health Care Performance Information?

© 2017, Springer International Publishing Switzerland. Background: Choosing a new health service provider can be difficult and is dependent on the type and clarity of the information available. This study examines if the presentation of service quality information affects the decisions of consumers choosing a general medical practice. Objectives: The aim was to examine the impact of presentation format on attribute level interpretation and relative importance. Methods: A discrete choice experiment eliciting preferences for a general medical practice was conducted using four different presentation formats for service quality attributes: (1) frequency and percentage with an icon array, (2) star ratings, (3) star ratings with a text benchmark, and (4) percentage alone. A total of 1208 respondents from an online panel were randomised to see two formats, answering nine choices for each, where one was a dominated choice. Logistic regression was used to assess the impact of presentation format on the probability of choosing a dominated alternative. A generalised multinomial logit model was used to estimate the relative importance of the attribute levels. Results: The probability of incorrectly choosing a dominated alternative was significantly higher when the quality information was presented as a percentage relative to a frequency with icon array, star rating or bench-marked star rating. Preferences for a practice did not differ significantly by presentation format, nor did the probability of finding the information difficult to understand. Conclusions: Quantitative health service quality information will be more useful to consumers if presented by combining the numerical information with a graphic, or using a star rating if appropriate for the context

Preferences for new and existing contraceptive products

New contraceptive methods provide greater choice in terms of effectiveness, management of side-effects, convenience and frequency of administration and flexibility, but make the decisions about contraception more complex. There are limited data on the factors that determine women's choices among these alternatives, to inform providers about the factors which are most important to women, or to predict uptake of new products. This paper reports on a choice experiment designed to elicit women's preferences in relation to prescribed contraception and to forecast the impact of the introduction of two new products into the Australian market. A generalised multinomial logit model is estimated and used in the simulation exercise. The model forecasts that the hormonal patch would be well received among women, achieving a greater market share than current non-pill products, but the vaginal ring would have limited appeal. Copyright © 2011 John Wiley & Sons, Ltd

Native Wildlife Adjust Activity Patterns to Temporally Avoid Wild Pigs

Wildlife species have defined activity patterns that are important for conserving biological rhythms and altering these rhythms can cause physiological stress. Species often shift activity patterns to minimize predation risks or to temporally partition competition. Thus, when a new predator or competitor is introduced into a community, the activity patterns of the whole community could be affected, and this effect may increase the stress wild pigs cause to native wildlife. To test the hypothesis that wild pig activity patterns affect those of native wildlife, we monitored activity patterns of native wildlife and wild pigs before and after aerial gunning events that manipulated pig activity patterns. Using the Statistical R-package – Overlap option, we generated species activity curves which showed aerial gunning caused a substantial shift in wild pig activity patterns from peaking near sunrise to peaking near sunset. Native species not directly at risk from aerial gunning, such as raccoon, armadillo, rabbits, squirrels, and opossum, shifted their activity patterns to a lesser degree than that of pigs, but most species adjusted activity peaks to favor lulls in pig activity. Thus, by manipulating swine activity patterns we provide evidence that wild pigs affect the activity patterns of many native wildlife species. Not only does our data demonstrate the flexibility of pigs to alter activity patterns to avoid removal, it also indicates that these animals cause an additional unappreciated stress on native wildlife by altering their biological rhythm

Consideration Sets and Their Role in Modelling Doctor Recommendations About Contraceptives

Copyright © 2015 John Wiley & Sons, Ltd. Decisions about prescribed contraception are typically the result of a consultation between a woman and her doctor. In order to better understand contraceptive choice within this environment, stated preference methods are utilized to ask doctors about what contraceptive options they would discuss with different types of women. The role of doctors is to confine their discussion to a subset of products that best match their patient. This subset of options forms the consideration set from which the ultimate recommendation is made. Given the existence of consideration sets we address the issue of how to model appropriately the ultimate recommendations. The estimated models enable us to characterize doctor recommendations and how they vary with patient attributes and to highlight where recommendations are clear and when they are uncertain. The results also indicate systematic variation in recommendations across different types of doctors, and in particular we observe that some doctors are reluctant to embrace new products and instead recommend those that are more familiar. Such effects are one possible explanation for the relatively low uptake of more cost effective longer acting reversible contraceptives and indicate that further education and training of doctors may be warranted. Copyright © 2015 John Wiley & Sons, Ltd

Estimation of transient increases in bleeding risk associated with physical activity in children with haemophilia

BACKGROUND: Although it is widely appreciated that vigorous physical activity can increase the risk of bleeding episodes in children with haemophilia, the magnitude of the increase in risk is not known. Accurate risk estimates could inform decisions made by children with haemophilia and their parents about participation in physical activity and aid the development of optimal prophylactic schedules. The aim of this study is to provide an accurate estimate of the risks of bleeding associated with vigorous physical activity in children with haemophilia. METHODS/DESIGN: The study will be a case-crossover study nested within a prospective cohort study. Children with moderate or severe haemophilia A or B, recruited from two paediatric haematology departments in Australia, will participate in the study. The child, or the child's parent or guardian, will report bleeding episodes experienced over a 12-month period. Following a bleeding episode, the participant will be interviewed by telephone about exposures to physical activity in the case period (8 hours before the bleed) and 2 control periods (an 8 hour period at the same time on the day preceding the bleed and an 8 hour period two days preceding the bleed). Conditional logistic regression will be used to estimate the risk of participating in vigorous physical activity from measures of exposure to physical activity in the case and control periods. DISCUSSION: This case-control study will provide estimates of the risk of participation in vigorous physical activity in children with haemophilia

Visualising Conversation Structure across Time: Insights into Effective Doctor-Patient Consultations

Effective communication between healthcare professionals and patients is critical to patients’ health outcomes. The doctor/patient dialogue has been extensively researched from different perspectives, with findings emphasising a range of behaviours that lead to effective communication. Much research involves self-reports, however, so that behavioural engagement cannot be disentangled from patients’ ratings of effectiveness. In this study we used a highly efficient and time economic automated computer visualisation measurement technique called Discursis to analyse conversational behaviour in consultations. Discursis automatically builds an internal language model from a transcript, mines the transcript for its conceptual content, and generates an interactive visual account of the discourse. The resultant visual account of the whole consultation can be analysed for patterns of engagement between interactants. The findings from this study show that Discursis is effective at highlighting a range of consultation techniques, including communication accommodation, engagement and repetition